Farmers strive for high crop yields. In the process of doing so, they may use excessive amounts of nutrient providing fertilizers. Most companies and individuals with lawns, gardens, golf courses, etc., want them to look green, fruitful and vibrant. In the process of doing so, they may use excessive amounts of fertilizers. Nutrient run-off and ground water contamination may be caused by excessive nutrient application to agricultural lands, golf courses, parks, nurseries, gardens, lawns, and other sites. The run-off of nutrients causes hypoxia may cause the death and growth inhibition of most aquatic life. Vivid examples are the dead zones in the Gulf of Mexico and Lake Erie. Surface water and ground water contamination with nutrients may cause increased potable water treatment costs, and expensive and complicated processes. The underlying issues are outlined in the report titled “Ceres Water Climate Risk Corn Report” dated June 2014 and “What is Hypoxia” dated Dec. 6, 2014 by Jennifer Iarino, Nola.com. Additional information can be found in the publication “COMING TOGETHER TO PROTECT MISSISSIPPI RIVER WATERSHEDS”, published by the U.S. Water Alliance, August 2014.
For millennia, agriculturists have demonstrated the effectiveness of natural (manures) and chemically synthesized fertilizers to increase farm crop yields. Increased farm yields depend on many factors. Fundamentally, farms are businesses. While yields for corn can range from 170 bushels/acre to 465 bushels/acre, the 50 percentile for yield is about 200 bushels/acre. In the final analysis, the farmer's basic objective is profit/return on investment. Value propositions are a way of life for farmers. High fertilizer addition rate equals improved profits for most farmers even though it causes nutrient runoff to waterways.
Plants require 16 nutrients to grow. Non-mineral nutrients include hydrogen, oxygen and carbon. These nutrients are found in the air and water. Plants use energy from the sun to change carbon dioxide and water into starches and sugars through photosynthesis. These starches are the plant's food. Since plants get carbon, hydrogen and oxygen from the air and water there is little farmers can do (other than locate plants in sunny areas/irrigate when rainfall is low) to control how much of these nutrients are available to the plants.
The 13 mineral nutrients, which come from the soil, are dissolved in water and absorbed through a plant's roots. There are not always enough of these nutrients in the soil for healthy plant growth. This is why many farmers use fertilizers to add the nutrients to the soil. The mineral nutrients are divided into two groups: macronutrients and micronutrients.
Macronutrients can be broken into two more groups: primary and secondary nutrients. The primary nutrients are nitrogen, phosphorus, and potassium. These major nutrients usually are lacking from the soil because plants use large amounts for their growth and survival. The secondary nutrients are calcium, magnesium, and sulfur. There are usually enough of these nutrients in the soil, so fertilization with secondary nutrients is not always needed.
The 7 micronutrients are those elements essential for plant growth which are needed in only very small quantities. These elements are boron, copper, iron, chloride, manganese, molybdenum and zinc. If required micronutrients are available in the soil, no supplemental addition is required.
Soils vary widely in composition, structure, and nutrient supply. Especially important from the nutritional perspective are inorganic and organic soil particles called colloids. Soil colloids retain nutrients for release into the soil solution where they are available for uptake by the roots. Soil colloids serve to maintain a reservoir of soluble nutrients.
The function of the colloidal soil fraction depends on two factors: (1) colloids present a large specific surface area, and (2) the colloidal surfaces carry a large number of charges. The charged surfaces in turn reversibly bind large numbers of ions, especially positively charged cations from the soil solution. This ability to retain and exchange cations on colloidal surfaces is the single most important property of soils, insofar as plant nutrition is concerned.
Colloidal clays supply predominately negative charges by virtue of the alumina and silica at the edges of the clay particle. Because colloidal carbon is derived largely from lignin and carbohydrates, it also carries negative charges arising from exposed carboxyl and hydroxyl groups.
Soil colloids are predominantly nonionic and anionically charged and, consequently, they do not tend to attract negatively-charged anions (in other words, the anion exchange capacity of soil colloids is relatively low). The result is that anions are not held in the soil but tend to be readily leached out by percolating ground water. This situation has important consequences for agricultural practice. Nutrients supplied in the form of anions must be provided in large quantities to ensure sufficient uptake by the plants. As a rule, farmers often find they must apply at least twice—sometimes more—the amount of nitrogen required for producing a crop.
Unfortunately much of the excess nitrate is leached into the ground water, and eventually finds it's way into wells or into streams and lakes, where it contributes to problems of eutrophication by stimulating the growth of algae. Similar issues relate to the inefficient uptake of negatively charged phosphorous (PO4=) and sulfur (SO4=) by plants, with subsequent problems resulting from nutrient runoff.
Plants vary on how much macronutrient (nitrogen, phosphorous, potassium) they require for robust growth. For example, corn requires high levels of nitrogen while legumes do not require any nitrogen as they are able to fix nitrogen requirements from the air.
There are three fundamental ways plants uptake nutrients through the root: 1) simple diffusion, occurs when a non-polar molecule, such as O2, CO2, and NH3 follows a concentration gradient, moving passively through the cell lipid bilayer membrane without the use of transport proteins; 2) facilitated diffusion, is the rapid movement of solutes or ions following a concentration gradient, facilitated by transport proteins; 3) Active transport is the uptake by cells of ions or molecules against a concentration gradient. This requires an energy source, usually ATP, to power molecular pumps that move the ions or molecules through the membrane.
Three of the important macronutrients, nitrogen, phosphorous and sulfur enter the plant cell wall in the form of anions. If these macronutrients are not retained in the soil in proper concentration to facilitate their transport across the plant cell wall, excess fertilization will be required to obtain optimum crop yields.
Methods being considered to control nutrient run-off include collection of run-off water and removal of nutrients. This increases pollution abatement capital and operating costs, and does not address ground water contamination or optimization of crop yields.
Another method being considered is to grow scavenger plants around the perimeter of agricultural fields to capture the excess nutrients. This does not address the wastage of fertilizer usage nor does it address ground water contamination or the desirability of increased crop yield.
Increase of the soil Cation Exchange Capacity “CEC” by usage of humic acid is neither efficient nor effective at addressing the need for retaining anions. The theory of increasing CEC is that ammonia while being a cation readily nitrifys to nitrates which are anions and thus not retained in the solid. Nitrification blockers are an additional expense and only partially effective. Frequently nitrogen is applied in the form of ammonium nitrate. The nitrate form of nitrogen is negatively charged and not affected by CEC. Further, phosphates and sulfates are also anions and not effectively retained by CEC.
Clays, which are the main source of CEC, have low efficiency, being less than 10% as efficient in retaining cations, than the proposed compositions of matter. Many cations in the soil and needed by plants are actually anion complexes and thus are not retained by CEC. Moreover, clays are weakly charged. As such, there is minimal inhibition of hydraulic leaching of bound cations during irrigation or rains.
The present invention addresses these issues in part.